Separable contact device



R. B. BENJAMIN.

SEPARABLE CONTACT DEVICE. APPLICATION FILED IUNE Z4, I9I5. 1,335,550, Patented Mar. 30,1920.

25 3 SHEETS-SHEET I. I

R. B. BENJAMIN. SEPABABLE CONTACT DEVICE. APPLIcAnoN FILED luNE 24. |915.

3 SHEETS-SHEET 2.

l NN N N Nr Nif Patented Mar. 30,1920.

R. B.BEN1AM1N.

SEPARABLE CONTACT DEVICE.

APPLIcAnoN FILED 1uNE24, |915.

1,335,550. Patented Mar. 30, 1920.

3 SHEETS-SHEET 3.

UNITED STATES ATENT OFFICE.

REUBEN B. BENJAMIN, CHICAGO, ILLINOIS, ASSIGNOR T() BENJAMIN ELECTRIC MANUFACTURING COMPANY, 0F CHICAGO, ILLINOIS, A CORPORATION 0F ILLINOIS.

SEPARABLE CONTACT DEVICE.

Application eld June 24,

To all whom t may concern:

Be it known that I, REUBEN B. BENJA- MIN, a citizen yof the United States, residing at Chicago, in the county oi' Cook and State of Illinois, have invented new and useful Improvements in Separable Contact Devices, of which the following is a full', clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

My invention relates to separable contact devices, and more specifically to such devices in which a 'binding terminal carrying member is provided with contacts for detachable engagement with the contacts of a device which is electrically connected with the supply circuit.

One of the objects of my invention is to provide an improved device of this cha-racter in which the binding terminal carrying member can engage the contacts of the device connected with the feed circuit in various positions, and in which it can easily be determined which one of the binding posts corresponds to the diii'erent contacts, and which is simple in construction and efficient in use.

Further objects will appear from the detailed description to follow and from the appended claims.

In the drawings in which I have shown several embodiments of my invention- Figure 1is an axial section of a separable attachment plug embodying my invention showing the manner in which the contacts are supported and engage each other;

Fig. 2 is a bottom view of the insertible portion of the plug, the cap being removed to show the relative arrangement of the contacts;

Fig. 3 is an axial section on the line 3--3 of Fig. 1 showing the manner in which the individual conductors are gripped:

Fig. 4 is a top plan view of the cap removed rom the insertible portion showing the arrangement ofthe concentric contacts;

Fig. 5 is a bottom view of one of the insulating members of the cap showing the binding screws and the cord gripping projection;

Fig. 6 is an axial section of a modified form of cap Fig. 7 is an axial section showingmy in- Vvention in connection with an adapter whereby my improved plug cap may be Specification of Letters Patent.I Patented llltll'. 30, 1920.

1915. Serial No. 36,006.

vention embodied in a connector in which my improved binding'terminal carrying cap detachably engages a binding terminal carrying member connected with the supply circuit.

Fig. 12 is an axial section on the line 12- 12 of Fig. 13 showing the manner in which the contacts are supported on one of the binding terminal carrying members I Fig. 13 is a section on the line 13-1'3 of Fig. 11 showing' the relative arrangement of the contacts;

Fig. 14 is a bottom view of one oftheg.'

members of the connector; and N Fig. 15 is a section onthe line 15-15 of Fig. 6. showing the manner in which the center contact is electricallyfconnected with its binding plate.

Referring now to the drawings in detail,

and first to the modification of Figs. l to 5 inclusive, I have here shown my invention in connection with a separable attach ment plug comprising an inserti'ble portion 20 which is t0 be screwed into a threaded shell receptacle and a cap or binding terminal carrying portion 21 provided with contacts for detachably engaging .the contacts of the insertible portion 20. The insertible portion 20 comprises an inner insulating part 22 and an outer insulating part 23 on which are supported a threaded shell contact 24 and a center Contact. 25. The part 22 is recessed, as shown at 26, to receive an extension or projection 27 on the part 22 to hold the parts in their proper elevated position. The shell contact 24 has an inwardly extending iangeportion 28 which is clamped in place between the parts 22 and 23. The center contact 25 is held in placel by means of a screw 29 which is threaded into a nut 30 seated in a recess 31 in the part 23, the screw 29 and nut 30 also serving to hold the parts 22 and 23 together and also to hold the U-shaped spring center contact 32 in place on the part 23. The contact 32- is provided with curved tips 33 for engagement with the center contact of t-he ca of the plug. The shell contact 24 is provided with spring tongues 34 formed integral therewith and extending through openings 35 in the part 23 and into an annular recess 36 in the outer face of the partv23. The-cap 21 comprises anv insulating portion 37 for supporting the binding terminals and contacts, and an insulating portion 38 acting as a cord grip and guide, and also as a housing for the binding terminals. The insulating portions 37 and 38 are held together by means of a sheet metal shell 39. For engagement with the spring tongues 34- the insulating portion 37 is provided with an annular contact memfber 40 which extends into the annular recess 36 and into contact with the spring tongues 34. For engagement with the center contact- 32 the portion 37 is provided with an inner annular contact member ,41 concentric with the contact 40. The annular contact member 40 is provided with an inwardly extending flange 42 having a portion 43 extending inwardly farther than the rest and; having an opening through which extends a bushing 44 which is riveted over the portion 43, as shown at 45, said bushing being threaded to receive one of the binding screws 46.

The insulating portion 37 is recessed, as

shown at 47, to expose the portion 43 so that one can tell by inspection to which one of the binding terminals the contact 40 is con-i nected. The portion 37 has a center projection or extension 48 for supporting the annular ycontact member 41. This contact member 41 comprises a knob-like portion 49 l and a reduced neck portion 50 for retaining it in place on the projection '48 and also 'for engagement with the curved-tips 33 of the` v contact 32 for detachably holding the contacts 41 and 32 in engagement. The center contact 41 is electrically. connected with its binding terminal by means of a bent conductor plate 51 having an enlarged head' 52, the contact 41 being bent inwardly below the head 52 to secure the parts firmly together and insure good -electrical contact (see Fig. 15). The plate 51 has a base portion 54 forming a binding plate with which the binding screw 55 has a screw threaded engagement. The portion 37 is recessed, as shown at 56, to disclose the base 54 sol that itcan be determined lby inspection to which one of the binding terminals the centery contact 41 isconnected.V :The insulating portion 38 is recessed, as shown at 57, to provide 'room for the conductors leading to the binding screws 46 and 55 and has a center opening 58 leading from the recess 57, `which opening may be tapered and screw threaded.' as shown at 58a in Fig. 1, to provide a means for holding the insulationof the cord 58b in place, or may be smooth as shown at 58c of the shell 39 which is beaded outwardly,l

as shown at 6l, so as to be spaced from the insulat-ing portion 37 and is flanged inwardly, as shown at 62, above the insulating portion 37.

The fact that the shell 39 is spaced -froln the insulating portion 37 renders the latter less liable to be cracked if the shell should strike against anything or receive a blow, than it would .if it were directly in contact with the insulating portion. The insulating portion 37 has a'central cord gripping projection 63 for engagement with the individual insulated conductors 64 of the cord 58h. The insulating portion 37 is recessed, as shown at 65, to receive the binding screws 46 'and 55. In wiring the cap shown in Fig. 1 the portions 37 and'. 38 are first separated by unscrewing the shell 39 and the portion 38.. The portion 38 is then threaded onto the cord 58b until the conductors 64 extend far enough through the opening 58 to permit them to be secured to the binding s`crews 46 and 55. The. portion v38 can then be screwed back on. the cord 58" until the portions 37 and 38 engage. each other properly, and the portions 37 and 38 can then be secured together by slipping the shell 39 over the portion 37 and threading it onto the portion 38 forcing the projection 63 into gripping engagement with the individual conductors 64. The principal purpose of the screw threads 58a is to hold theinsulation of the cord 58b firmly to prevent its being frayed, while the purpose of the cord gripping projection 63 is to hold the cords so as to take the strain ofi" of the binding terminals.

It will be noted that the cap 21 is held in place on the insertible portion 2O principally bythe engagement of the contacts 41 and 32 as the outer contacts 40 and 34 -have no curved interengaging portions. The fact that the contacts 34 and 40 have no curved interengaging portions enables the annular recess 38 to be made narrower than it cou'ld otherwise be made and still permit proper annular separation of the cap 21 from the insertible portion 20.

l The circuit through the plug is from the center contact 25, through the screw 29, cenand 4contacts 40 and 34, to the threaded shellV contact 24. With this plugit will be noted that after the cap has been wired'the same cord terminal will always-be connected electrically-with the center-contact 25 of the insertible portionI It will be noted that in drawing-the portions 37 and 38 together to clamp the individual conductors of the cord there is no relative rotation between the portions 37 and 38 which permits of the opening 58 being screw threaded to hold the insulation of the cord 58b firmly in place.

In Fig. 6 I have shown a modification of 'the cap; the contacts 40, and 41, the binding screws 46 and and the conducting plate 51 being, however, essentially similar to the corresponding parts of the modification of Fig. 1. In this modification the cap comprises an insulating portion 66 carrying the contacts and binding terminals, and an insulating portion 67 acting as a cord grip and cord guide, and also as a housing for the binding terminals. The portion 66 is provided with a central cord gripping project-ion 69 coperating with the'edge of the center opening 70 of the portion -67 to grip the individual conductors of the cord; the portions 66 and 67 have a threaded connection 68.

In wiring the cap of this modification the portions 66 and 67 are separated by unscrewing them, theportion 67 is slipped over the cord 58b a sufficient distance to enable the individual conductors 64 to be secured to the binding screws 46 and 55, after which the portion 67 is slipped back along the cord land threaded into the portion 66 to.

grip the individual conductors 64.

In Figs. 7, 8, 9 and 10 I have shown my invention in connection with an adapter by means of which the cap of Figs. 1 to 6 inclusive, may be used in connection with the insertible portion of a plug of a type now in use. In this form of my lnvention the binding terminal carrying cap is substantially the same as that shown in Fig. 6 and comprises the contacts 40 and 41 and insulating portions 66 and 67. The adapter comprises an insulating contact carrying member 71 to which are secured the contact blades 72 and 73 which engage the contact blades 72":L and 73a of the insertible portion of a known type of contact plug. The contact blade 73 is electrically connected with a U-shaped center Contact 74, and the contact blade 72 is electrically connected with an outer con'- tact member 75 having contact tongues 76 which extend through openings 77 into an annular recess 78 in the insulating member 71. The contact blade 72 is secured to the insulating member 71 by means of a screw 79 which extends through an opening 8O in the base portion 81 of the contact blade 72 and also extends through an opening 82 in the contact member 7 5 into screw threaded engagement with a bushing 83 embedded in the insulating member 71. The contact 4 blade 73 is secured to the member 71 by means of a screw 84 which extends through screw 84 also serving to hold the contact 74 in place. The contacts 40 and 41 of the cap engage the contacts 74 and 7 5 of the adapter in the same manner in which the corresponding contacts in the modification of Figs. 1-5 engage. The engagement between the contacts 41 and 74 and between the contacts 72 and 72a, and 73 and 73a is such that the cap will separate more readily from the adapter than the adapter will separate from the insertible portion .so that after the adapter is put in vplace it will not be removed when the cap is separated from the adapter. It will thus be seen that I have provided an adapter for the insertible portion of a known type of plug which will insure that the same contact of the cap will always be brought into electrical connection with the same contact of the insertible portion; that is, if the blade 73 is electrically connected with the center contact of the insertible portion, the center contact 41 of the cap will always be electrically connected with the center contact of the insertible portion whenever the cap is secured to the adapter.

In Figs. 11 to 14 inclusive, I have shown my invention in connection with an insulating binding terminal and contact carrying member 89 forming part of a separable connector provided with binding screws 90 and 91 and an insulating cord guide 92 which also serves 'as a housing for the binding screws. The member 89 and the cord guide 92 are secured together by means of a sheet metal shell or cap 93 having a screw threaded engagement with the insulating member 89 as shown at 94. The binding screw 90 extends through an opening in a conductor plate 95 and into screw threaded engagement with a bearing 96 embedded in the insulating member 89. TheA conductor plate 95 is connected to the center contact 97 by means of a hollow rivet 'or eyelet 98. The binding screw 91 extends through an opening in a contact member 99 of sheet metal and through an opening in an insulating plate 100 of mica or other suitable material into threaded engagement with a nut 101 embedded in the member 89. The member 99 is secured to the member 89 by means of hollow rivets or eyelets 102 embedded in the member 89 and flanged over above the member 99 as shown at 103. The contact member 99 is provided with contact tongues 104 formeel integral therewith and extending through openings 105 into an annular recess 106 formed in the insulating member 89. The cap shown in connection with this connector member is substantially the same as the cap shown in Fig. 6 and comprises the contacts 40 and 41 and the insulating portions 66 and 67.

In wiring the upper portion of the connector the member 92 is separated from the member 89 by unscrewing the shell 93 and the member 92 is slipped over the ends of the leading in wires. The conductors are then secured under thev binding screws 90 and 91 and the member 92 is slipped back into engagement with the member 89 and the members 92 and 89 are secured together by threading the shell 93 onto the member 89. The insulating plate 1 00 lies between the contact member 99 and the hollow rivet 9S and prevents short circuiting at this point. The circuit through this connector is from the binding screw 90 through the plate 95, contacts 97 and 41 and cord circuit, to the contact 40, through the Contact tongues 104, to the contact member 99 and binding post 91.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is l l. In a device of the class described, the combination with an insulating basehaving opposite faces and an annular recess in one of said faces, of a contact comprising a portion engaging the other of said faces and having a portion integral with said first portion extendingv into said recess.

2. In a device of the class described, the combination with an insulating base having opposite faces and an annular recess in one of said faces, and an opening leading from said recess to the other face, of a contact comprising a portion engaging the other of said faces and having a portion integral 'with said first portion extending through said opening into said recess.

3. In a device of the class described, an insulating base comprising two insulating portions, a contact shell having a portion extending inward between said insulating portions, one of said insulating portions having an annular recess, and a contact extendinginto said annular recess and Aelectrically connected to said inwardly exftending portion.

4.-. In a device of the class described, an 4insulating vbase comprising two insulating portions, a contact shell having aportion extending inward between said insulating portions, onel of said insulating portions having an annular recess, and a contact extending into said annular recess and electrically connected to said inwardly extending portion, said last named Contact being integral with said inwardly extending portion. 5. In a contact device a substantially cylindrical insulating base, a contact carried thereby, a binding screw electrically connected to said contact extending substantially parallel' to the axis of said cylindex` and supported thereby, land a two-part housing for said base and screw, .said housing comprising an insulating portion constituting a 'cord gripping member.

6. In a- Contact device a substantially cycontact having a portion extending between lindrical insulating base, a contact carried thereby, a binding screw electrically con! nected to said contact extending substantially parallel to the axis of said cylinder and supported thereby, and a two-part housing for said base and screw, said housing comprising an insulating portion forming a thumb piece andv a sheet metal shell portion 1 for holding said thumb piece on said base.

7. In a contact device a substantially cylindrical insulating base7 a contact carried thereby, 'a binding screw electrically connected to said contact extending substantially parallel to the axis of said cylinder and supported thereby, a two-part housing for said base and screw, said housing comprising an insullating portion forming a thumb piece and a sheet meta-l shell portion for holding said thumb piece on said base, said thumb piece and shell having a screw threaded engagement lwith each other.

8. In a contact device a substantially cylindrical insulating base, a conductor supported thereby, andan annular sheet metal casing means surrounding said base and beaded outwardly from said base to provide a space between said base and casing means to lessen the danger of breaking the base by jarring it.

9. In a contact device an insulating base', a contact carried thereby, and a housing for said base comprisingi sheet metal casing means surrounding said base land beaded outwardly from said base to provide a space between said base and casing means, and a thumb piece having a screw threaded engagement with said sheet metal casing means.

10. In a connector, an insulating base comprising two insulating portions, a shell said insulating portions, a center contact supported by said base, "means for holding said last contact on said base, and said insui lating portions together comprising a member extending through both said insulating portions, a binding terminal carrying member and contacts supported thereby for engaging said shell and center contacts respectively.

11. In a connector, an insulating base 115 A comprising two insulating portions, a shell contact having a portion extending between said insulating'portions, a contact carrled on said base for detachably engaging another contact, and means for holding said contact on said base and said insulating portions together comprising a member extending through both said insulating port1ons.

12. In a connector, an insulating base comprising two insulating portions, a shell contact having a portion extending between said insulating portions, a Contact carried on said base for detachably engaging another contact, and means for holding said contact on said base and said `insulating portions together comprising a screw extending through both said insulating portions.

13. A contact device comprising an insulating member having a center recess and an annular recess surrounding said center recess, a second insulating member, a center contact supported thereby, a shell contact surrounding said second insulating member, a contact in said center recess electrically connected to said center contact, and

a contact in said annular recess electrically.

connected to said shellcontact.

14. A contact device comprising an insulating member having a center recess and an annular recess surrounding said center recess, a second insulating member, a cen- 'ter contact supported thereby, a shell contact' surrounding said second insulating member, a contact in said center recess electrically connected to said center contact, and a contact in said annular recess integral with said shell contact.

15. A contact device comprising an insulating member having a center recess and an annular recess surrounding said center recess, a second insulating member, a center contact supported thereby, a shell contact surrounding said second insulating member, a contact in said center recess electrically ,connected to said center contact, a contact` in said annular recesselectrically connected to said shell contact, and a binding terminal carrying portion having an annular contact for entering said annular recess to en-l l gage the contact therein, and a contact for entering said center recess to 'engage the contact therein.

16. In a connector an insulating base hav-` ing a center recess, and an annular recess surrounding. said center recess, contacts 1n said recesses, an insulating member, binding a second insulating member having a screw threaded opening therein, of a size to grip the insulation of an insulated cord carrying two insulated conductors, said two members being provided with coperating means for gripping the insulation of the Lindividual conductors, and means for drawing the two insulating members toward each other without relative rotation therebetween to clamp the individual conductors.

18. In a connector an insulating member, a` pair Yof binding terminals carried thereby, a second insulating member having a screw threaded opening therein of a size to grip the insulation of an insulated cord carrying two insulated conductors, said two members being provided with coperating means for gripping the insulation of the individual conductors, and means for drawing the two insulating members toward each other without relative rotation therebetween to clamp the individual conductors, said last means comprising a sheet metal shell having an abutment engaging one of said -ins'ulating members and y having a screw threaded engagement with the other.

In Witness whereof I have hereunto subscribed my name.

REUBEN B. BENJAMIN.- 

